Stable and Efficient Upconversion Single Red Emission from CsPbI₃ Perovskite Quantum Dots Triggered by Upconversion...

Area of Science:

• Materials Science
• Nanotechnology
• Photonics

Background:

• Upconversion nanoparticles (UCNPs) offer unique light emission properties but often require specific excitation wavelengths.
• Perovskite quantum dots (PQDs) exhibit efficient luminescence, but their stability can be a challenge.
• Developing multifunctional materials with tunable optical properties is crucial for advanced applications.

Purpose of the Study:

• To synthesize stable composites of inert shell-modified NaYF4:Yb/Tm@NaYF4 upconversion nanoparticles (UCNPs) and CsPbI3 perovskite quantum dots (PQDs).
• To achieve efficient and tunable red emission from these UCNP-PQD composites.
• To demonstrate the potential of these composites for dual-mode anti-counterfeiting applications.

Main Methods:

• Synthesis of UCNPs and CsPbI3 PQDs using (3-aminopropyl)triethoxysilane (APTES) as a precursor for a SiO2 matrix.
• Characterization of the composite structure for stability under ambient conditions.
• Tuning the red emission wavelength by incorporating bromide (Br-) ions.

Main Results:

• Successful synthesis of stable UCNP-PQD composites with efficient upconversion (UC) and downshifting (DS) red emission.
• Achieved tunable single red emission from 705 to 625 nm by adjusting Br- ion concentration.
• Demonstrated dual-wavelength excitation characteristics due to the combined UC and DS emissions.
• Validated the potential for dual-mode anti-counterfeiting applications.

Conclusions:

• The developed UCNP-PQD composites exhibit excellent stability and tunable red emission, overcoming limitations of traditional UCNPs.
• The dual-mode excitation and tunable emission properties make these composites highly suitable for advanced anti-counterfeiting strategies.
• This work presents a novel approach for designing multifunctional perovskite-based materials.